Many high-performance endurance athletes undertake specialized forms of altitude training. The lack of agreement regarding the effects of altitude training on hematology and performance is partially explained by various differences in the methodology of altitude training studies. 1 For example
Ida A. Heikura, Louise M. Burke, Dan Bergland, Arja L.T. Uusitalo, Antti A. Mero and Trent Stellingwerff
Henry N. Williford, Michele Scharff Olson, Robert E. Keith, Jeffrey M. Barksdale, Daniel L. Blessing, Nai-Zhen Wang and Pete Preston
This investigation evaluated the iron and nutritional status of 12 highly trained aerobic dance instructors who did not take iron supplements (ANS) and 8 who did (AS). A control group (C) consisted of 10 age matched controls. The aerobic instructors had exercised for approximately 3.8 days/wk, 56 min/session for the past 7 yrs. There were no significant differences among groups for energy intake, carbohydrate, protein, fat, nonheme iron, heme iron, or total iron intake (excluding supplemental iron). But both exercise groups had lower ferritin values than the control group. There was also a significant difference in mean cell volume (MCV), with both exercise groups having greater values than the control group. There were no differences among groups for serum iron, total iron binding capacity, transferrin saturation, hematocrit, or hemoglobin. One in three aerobic dance instructors had serum ferritin values below 12 μg · L−1. Results indicate that women exercise leaders have iron profiles that are similar to other groups of female athletes. The increased MCV values suggest runners' macrocytosis or an exercise induced macrocytosis.
Lawrence E. Armstrong, Roger W. Hubbard, E. Wayne Askew, Jane P. De Luca, Catherine O'Brien, Angela Pasqualicchio and Ralph P. Francesconi
This investigation examined whether low sodium (Na+) (LNA; 68 mEq Na+·d-1) or moderate Na+ (MNA; 137 mEq Na+.d-1) intake allowed humans to maintain health, exercise, and physiologic function during 10 days of prolonged exercise-heat acclimation (HA). Seventeen volunteers, ages 19 to 21, consumed either LNA (n=8) or MNA (n=9) during HA (41°C, 21% RH; treadmill walking for 30 min.h-1, 8 h·d-1 at 5.6 kmh-l, 5% grade), which resulted in significantly reduced heart rate, rectal temperature, and urine Na+ for both groups. There were few between-diet differences in any variables measured. Mean plasma volume in LNA expanded significantly less than in MNA by Days 11 and 15, but reached the MNA level on Day 17 (+12.3 vs. +12.4%). The absence of heat illness, the presence of normal physiologic responses, and the total distance walked indicated successful and similar HA with both levels of dietary Na+.
Darrell L. Bonetti, Will G. Hopkins, Timothy E. Lowe and Andrew E. Kilding
Adaptation to acutely intermittent hypoxic exposure appears to produce worthwhile enhancements in endurance performance, but the current 5-min duration of hypoxia and recovery intervals may not be optimal.
Eighteen male competitive cyclists and triathletes were randomized to one of two intermittent-hypoxia groups, and nine similar athletes represented a control group. Athletes in the hypoxia groups were exposed to 60 min per day of intermittent hypoxia consisting of alternating intervals of hypoxia and normoxia lasting either 3 or 5 min. Exposures were performed at rest for 5 consecutive days per week for 3 wk. Oxygen saturation, monitored with pulse oximetry, was reduced progressively from 90% (day 1) to 76% (day 15). All athletes maintained their usual competitive-season training throughout the study. Incremental and repeated-sprint tests were performed pre, 3 d post, and 14 d post intervention. Venous blood at rest was sampled pre, mid-, and postintervention.
There were no clear differences between effects of the two hypoxic treatments on performance or various measures of oxygen transport, hematopoiesis, and inflammation. Compared with control, the combined hypoxic groups showed clear enhancements in peak power (4.7%; 90% confidence limits, ±3.1%), lactate-profile power (4.4%; ±3.0%), and heart-rate profle power (6.5%; ±5.3%) at 3 d post intervention, but at 14 d the effects were unclear. Changes in other measures at 3 and 14 d post intervention were either unclear or unremarkable.
Acutely intermittent hypoxia produced substantial enhancement in endurance performance, but the relative benefit of 3- vs 5-min exposure intervals remains unclear.
Blair Crewther, Konrad Witek, Paweł Draga, Piotr Zmijewski and Zbigniew Obmiński
measures would be negatively related to initial T levels. As a secondary aim, we investigated other indicators of physical function and blood hematology, but no firm hypotheses were made regarding these outcomes. Methods Subjects A total of 16 male climbers with a mean (± SD ) age of 35.4 ±7.3 years
Nathan A. Lewis, Ann Redgrave, Mark Homer, Richard Burden, Wendy Martinson, Brian Moore and Charles R. Pedlar
Purpose: To examine a diagnosis of unexplained underperformance syndrome (UUPS, or overtraining syndrome) in an international rower describing a full recovery and return to elite competition the same year. Methods: On diagnosis and 4 and 14 mo postdiagnosis, detailed assessments including physiological, nutritional, and biomarkers were made. Results: Clinical examination and laboratory results for hematology, biochemistry, thyroid function, immunology, vitamins, and minerals were unremarkable and did not explain the presentation and diagnosis. Redox biomarkers including hydroperoxides, plasma antioxidant capacity, red blood cell glutathione, superoxide dismutase, coenzyme Q10, vitamin E (α- and γ-tocopherol), and carotenoids (lutein, α-carotene, β-carotene) provided evidence of altered redox homeostasis. The recovery strategy began with 12 d of training abstinence and nutritional interventions, followed by 6 wk of modified training. At 4 mo postintervention, performance had recovered strongly, resulting in the athlete’s becoming European champion that same year. Further improvements in physiological and performance indices were observed at 14 mo postintervention. Physiologically relevant increases in concentrations of carotenoids were achieved at each postintervention time point, exceeding the reported critical-difference values. Conclusions: Increasing athlete phytonutrient intake may enhance recovery and tolerance of training and environmental stressors, reducing the risk of unexplained UUPS. Alterations in redox homeostasis should be considered as part of the medical management in UUPS. This is the first reported case study of an elite athlete with alterations in redox homeostasis in conjunction with a diagnosis of UUPS.
Ronald J. Maughan
. International Journal of Sport Nutrition and Exercise Metabolism, 28 ( 2 ), 104 – 125 . 10.1123/ijsnem.2018-0020 Watson , P. , & Maughan , R.J. ( 2014 ). Artifacts in plasma volume changes due to hematology analyzer derived hematocrit . Medicine & Science in Sports & Exercise, 46 , 52 – 59 . doi:10
Blake D. McLean, Kevin White, Christopher J. Gore and Justin Kemp
2 measurements, whereas a different hemoximeter (ABL80; Radiometer Medical ApS) was used during year 3 . Venous blood samples collected in Melbourne (ie, all samples excluding year 2 measurements at altitude) were analyzed using a Sysmex XE-5000 automated hematology analyzer (Roche Diagnostics
Kadhiresan R. Murugappan, Michael N. Cocchi, Somnath Bose, Sara E. Neves, Charles H. Cook, Todd Sarge, Shahzad Shaefi and Akiva Leibowitz
– 180 . PubMed ID: 28902675 doi:10.1097/ALN.0000000000001878 10.1097/ALN.0000000000001878 Thompson , A.A. ( 2013 ). Sickle cell trait testing and athletic participation: A solution in search of a problem? Hematology. American Society of Hematology. Education Program, 2013 , 632 – 637 . PubMed ID
Lee Smith, Brendon Stubbs, L. Hu, Nicola Veronese, Davy Vancampfort, Genevieve Williams, Domenico Vicinanza, Sarah E. Jackson, Li Ying, Guillermo F. López-Sánchez and Lin Yang
/L were excluded, because such levels may represent an acute infective episode. WBCs were counted with Coulter HMX Hematology Analyzer (Beckman Coulter, CA), a quantitative, automated hematology analyzer and leukocyte differential cell counter for in vitro diagnostic use in clinical laboratories. Serum